The tongue is a muscular organ in the mouth of a typical tetrapod. It manipulates food for chewing and swallowing as part of the digestive process, and is the primary organ of taste. The tongue's upper surface (dorsum) is covered by taste buds housed in numerous lingual papillae. It is sensitive and kept moist by saliva and is richly supplied with nerves and blood vessels. The tongue also serves as a natural means of cleaning the teeth. A major function of the tongue is the enabling of speech in humans and vocalization in other animals.
The esophagus or oesophagus, colloquially known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the stomach. The esophagus is a fibromuscular tube, about 25 cm (10 in) long in adults, that travels behind the trachea and heart, passes through the diaphragm, and empties into the uppermost region of the stomach. During swallowing, the epiglottis tilts backwards to prevent food from going down the larynx and lungs. The word oesophagus is from Ancient Greek οἰσοφάγος (oisophágos), from οἴσω (oísō), future form of φέρω + ἔφαγον.
Swallowing, sometimes called deglutition in scientific contexts, is the process in the human or animal body that allows for a substance to pass from the mouth, to the pharynx, and into the esophagus, while shutting the epiglottis. Swallowing is an important part of eating and drinking. If the process fails and the material goes through the trachea, then choking or pulmonary aspiration can occur. In the human body the automatic temporary closing of the epiglottis is controlled by the swallowing reflex.
The glossopharyngeal nerve, also known as the ninth cranial nerve, cranial nerve IX, or simply CN IX, is a cranial nerve that exits the brainstem from the sides of the upper medulla, just anterior to the vagus nerve. Being a mixed nerve (sensorimotor), it carries afferent sensory and efferent motor information. The motor division of the glossopharyngeal nerve is derived from the basal plate of the embryonic medulla oblongata, whereas the sensory division originates from the cranial neural crest.
The nucleus ambiguus is a group of large motor neurons, situated deep in the medullary reticular formation named by Jacob Clarke. The nucleus ambiguus contains the cell bodies of neurons that innervate the muscles of the soft palate, pharynx, and larynx which are associated with speech and swallowing. As well as motor neurons, the nucleus ambiguus contains preganglionic parasympathetic neurons which innervate postganglionic parasympathetic neurons in the heart.
The styloglossus muscle is a bilaterally paired muscle of the tongue. It originates at the styloid process of the temporal bone. It inserts onto the side of the tongue. It acts to elevate and retract the tongue. It is innervated by the hypoglossal nerve.
The salpingopharyngeus muscle is a muscle of the pharynx. It arises from the lower part of the cartilage of the Eustachian tube, and inserts into the palatopharyngeus muscle by blending with its posterior fasciculus. It is innervated by vagus nerve via the pharyngeal plexus. It raises the pharynx and larynx during deglutition (swallowing) and laterally draws the pharyngeal walls up. It opens the pharyngeal orifice of the Eustachian tube during swallowing to allow for the equalization of pressure between it and the pharynx.
The middle pharyngeal constrictor is a fan-shaped muscle located in the neck. It is one of three pharyngeal constrictor muscles. It is smaller than the inferior pharyngeal constrictor muscle.
The inferior pharyngeal constrictor muscle is a skeletal muscle of the neck. It is the thickest of the three outer pharyngeal muscles. It arises from the sides of the cricoid cartilage and the thyroid cartilage. It is supplied by the vagus nerve. It is active during swallowing, and partially during breathing and speech. It may be affected by Zenker's diverticulum.
The superior pharyngeal constrictor muscle is a quadrilateral muscle of the pharynx. It is the uppermost and thinnest of the three pharyngeal constrictors.
The stylopharyngeus muscle is a muscle in the head. It originates from the temporal styloid process. Some of its fibres insert onto the thyroid cartilage, while others end by intermingling with proximal structures. It is innervated by the glossopharyngeal nerve. It acts to elevate the larynx and pharynx, and dilate the pharynx, thus facilitating swallowing.
The pharyngeal arches, also known as visceral arches, are structures seen in the embryonic development of vertebrates that are recognisable precursors for many structures. In fish, the arches are known as the branchial arches, or gill arches.
The inferior thyroid artery is an artery in the neck. It arises from the thyrocervical trunk and passes upward, in front of the vertebral artery and longus colli muscle. It then turns medially behind the carotid sheath and its contents, and also behind the sympathetic trunk, the middle cervical ganglion resting upon the vessel.
The ascending pharyngeal artery is an artery of the neck that supplies the pharynx.
The superior laryngeal nerve is a branch of the vagus nerve. It arises from the middle of the inferior ganglion of vagus nerve and additionally also receives a sympathetic branch from the superior cervical ganglion.
The ascending palatine artery is an artery is a branch of the facial artery which ascends along the neck before spliting into two terminal branches; one branch supplies the soft palate, and the other supplies the palatine tonsil and pharyngotympanic tube.
The pharyngeal branch of the vagus nerve is the principal motor nerve of the pharynx. It represents the motor component of the pharyngeal plexus of vagus nerve and ultimately provides motor innervation to most of the muscles of the soft palate, and of the pharynx.
The pharyngeal plexus is a nerve plexus located upon the outer surface of the pharynx. It contains a motor component, a sensory component, and sympathetic component.
The pharyngeal artery is a branch of the ascending pharyngeal artery. The pharyngeal artery passes inferior-ward in between the superior margin of the superior pharyngeal constrictor muscle, and the levator veli palatini muscle. It issues branches to the constrictor muscles of the pharynx, the stylopharyngeus muscle, the pharyngotympanic tube, and palatine tonsil; a palatine branch may sometimes be present, replacing the ascending palatine branch of facial artery.
The pharynx is the part of the throat behind the mouth and nasal cavity, and above the esophagus and trachea. It is found in vertebrates and invertebrates, though its structure varies across species. The pharynx carries food to the esophagus and air to the larynx. The flap of cartilage called the epiglottis stops food from entering the larynx.
